A number of rotatable elements, particularly in the field of machine tools have within them various movable components which are actuated by fluid under pressure such as compressed air. An example of such a machine tool is a chuck having air actuated jaws for clamping the workpiece. Such tools require a source of air under pressure while the tool is stationary with the air source being disconnected from the tool during tool rotation. A number of devices have been developed to provide fluid delivery means to a temporarily stationary tool such as a chuck. Once the mechanism within the tool has been fully actuated, suitable check valve means seals the fluid within the tool and the air source is disconnected. However, heretofore there has been no effective means which automatically and positively disengages the fluid source and tool during tool rotation. This has caused a number of problems particularly rapid wear of the seal which must be provided while the tool is being charged. The excessive wear results from frictional engagement, even though it may be slight, between the seal and the tool when the tool is being rotated. Even slight contact results in rapid and excessive wear. This invention overcomes these problems by providing means which effects a positive seal with the tool during fluid delivery and positive release during tool rotation.